Carburetor



Jan. 10, 1933. W., M, THOMAS @935,754

CARBURETOR Filed April 18. 1931 L\\\\\\ Ay /f/ C11-'Cor 114145 Fatented dan. lll, lg3d WILLIAM Ill. THOMAS, OF ALBUQUERQ'UE, NEW MEXICO CARBUBETOR Application filed April lS, 1931. Serial No. 531,*177.

'l` his invention relates to an improvement in devices for mixing a gas and a liquid and particularly to the class of these devices known as carburetors which are used to apply an explosive mixture to an internal combustion engine.

This device employs the conventional float chamber for supplying liquid under a constant head. An air passage is formed adjacent the float chamber and nozzles connected to the float chamber project into this passage to supply fuel therefrom to the gas flowing through the passage. As is customary, the nozzles terminate at a height sutilcient to prevent the fuel from the float chamber from flowing through them except when suction is applied to them by the Howing of air tirough the passage.

Obviously, this passage must be so formed as to produce a suction at the ends of the nozzles when air is flowed through it. The usual way to do this is by forming a constriction around the nozzles as is done in carburetors known as the Venturi type. rl`here are several objections to this type of carburetor mainly owing to the resistance offered to the passage of the gas, which prevents the internal combustion engine from sucking a large charge through the carburetor quickly, when desired. There is also an objection based on the fact that the mixture supplied by such a carburetor is not properly proportioned for all speeds and conditions of normal engine operation.

rlhis invention has for its object an improved mixing device which overcomes these objections. This device produces a suction at the ends of he nozzles by a means different fronithat of the Venturi carburetor while it does not offer the same resistance to the liow of gas therethrough, and yet provides a means for properly proportioning the mixture at all times.

This invention comprises a carburetor of the usual form in so far as float chamber, nozzles, choke valve and throttle valve are concerned, but the passage at the point at which the mixing takes place is new and different and the nozzle sizes are adjusted to function with this improved form.

' lower end.

The passage through the new carburetor comprises a horizontal and a vertical portion and the nozzles terminate in the lower end of the vertical passage. The vertical portion of the main passage is practically of the amount of gas to be by-passed around the liquid or fuel nozzles may be apportioned as desired.

The cylinder, instead of having the ends cut straight across, has each end cut in the shape of one turn of a helix with the ends of each turn connected by an approximately vertical line. 'llie pitch of the helix at the upper end is steeper than of the one at the The air striking the lower end as it comes in from the horizontal passage is given a swirling or helical motion as it is drawn into the cylinder and thus applies a suction to the nozzles and causes a mixing of the atomized fuel, gas and vapor as it leaves he cylinder.

he` cylinder is preferably of slightly smaller inside diameter at a point a short distance above the bottom end and tapers outwardly towards both ends. The taper is necessarily sharper towards the bottom in order that it may reach the outer circumference of the cylinder at the bottom of the cylinder. rlhe cylinder is preferably supported in the main passage by laterally extending lugs engaging notches in the passage wall but may be supported in any other desired manner.

ln a modilication which is especially satisfactory, the cylinder is offset slightly from the center of the main passage towards one side. This alters the shape of the surrounding or by-pass passage and in many instances improves the results obtained. Also, the rear half of this surrounding passage may be closed, that is only a half circle of passage provided. This half circle of .passage is preferably on the side of the cylinder from which the incoming gas approaches. lVith the cylinder set off-center this passage is wider toward one side edge thereof and becomes narrower as the passage extends around the cylinder.

For specific illustrations of the preferred embodiments of the applicants invention, reference may be had to the accompanying drawing, in which; l

Figure l is a side elevation, partly in section.

Figure 2 is a partial plan View with the top half of the carburetor removed to show the cylinder in place.

Figure 3 is a perspective of the inside cylinder.

Figure 4 is a side View of the inside cyliner.

Figure 5 is a partial section in side elevation showing a modified form of this inven tion, and

Figure 6 is a top view of the cylinder of the modification shown in Figure 5.

Referring to Figures l to 4 the reference character l designates a casting forming the lower part of the carburetor and 2, a casting forming the upper part of the carburetor. These two castings enclose a float chamber, not shown, and form a passage made up of a horizontal section 3 and a vertical section 4, shown in section in Figure l. Gas is adapted to flow into the passage 3 and its ilow may be controlled when desired by a choke valve 5 located near the entrance of the passage 3. Gas entering the passage 3 passes therethrough and upwardly into and through passage 4, and thence to the manifold of an internal combustion engine. A butterfly valve 6 controls the flow of gas from the passage 4.

In the passage 4 at its lower end is located a cylinder lO of smaller outside diameter than the inside of the passage 4 and supported in the passage 4 by radially extending lugs ll extending into notches l2 in the walls of the passage 4. rllhe cylinder l0 is hollow and open at both ends. The outside is cylindrical in form and the ends thereof are each out in the shape of one turn of a helix with the ends thereof oined. T he pitch of the helix forming the top of the cylinder is considerably greater than the pitch of the helix forming the bottom of the cylinder. The inside of the cylinder has a constricted portion 13 a short distance above the lower edge of the cylinder and the inside-of the cylinder tapers outwardly to meet the outside of the cylinder at both ends. This taper is sharper towards the bottom end of the cylinder on account of the shorter distance from the eonstricted portion to the bottom end. Except for the pitch the helix forming the bottom and the helix forming the top of the cylinder are the same,

that is, they progress in the same direction. Each end appears as one turn of a helix with the ends thereof joined by a substantially vertical line. This vertical line is on one side for the bottom and on the other side for the top end of the cylinder. rlfhe portion which extends farthest downward is located away from the side from which the gas enters from thc passage 3.

Nozzles are provided as indicated at 2() and 2l for supplying fuel to the gas. These n0zzles extend upwardly from the bottom of the passage 3 in the casting l and terminates slightly below the cylinder l0. These nozzles are supplied by the fuel from a float chamber which is not shown.

The conventional parts of the carburetor such as the float chamber, choke valve and mixture regulating mechanism 25, the idler nozzle 26 and the gasoline inlet 27, need not be described in detail as they are well known in the art.

ln the embodiment shown in Figures 5 and G the cylinder l0 is replaced by a similaicylinder 30 having a constricted portion 33, but this cylinder is supported in the passage 4 by a ring 3l adapted to be held in place by a groove 32 in the wall of the passage. The cylinder 30 is set eccentrically towards one side in the ring and only a half of the space between the cylinder and ring is left open. The half of this space which lies on the side farthest from the intake is sealed as shown at 34, leaving only a semi-circular opening 35 which is wider at the side edge 3G than at the side edge 34. rfhe rest of the construction of this modification is the same as that of the previously described embodiment and hence it will not be described in detail.

The operation of the device is as follows:

T he air or other gas entering through the passage 3 passes upwardly around the nozzles 20 and 2l and a part thereof through the cylinder l0. Upon striking the helically formed edge of the cylinder l0 this air is given a. spiral or helical motion and passing through the cylinder l0 past the constriction 13 causes a suction on the nozzles 20 and 2], thus drawing fuel therefrom which is mixed with the flowing Another portion of the gas flows upward between the walls of the passage 4 and the outside of the cylinder 10. As the gas on the inside of the cylinder l0 reaches the top of the cylinder it is released over the edge of the helix forming the top edge of the cylinder and mixes with the gas flowing around the outside of the cylinder. The gas from the inside of the cylinder l0 still has a helical motion which is accelerated by the helix at the top of the cylinder and this motion causes a particularly eflicient mixing of the atomized fuel, gas and vapor in the passage 4. By properly proportioning the size of the cylinder l0 to the size of the passage 4, the amount of gas by-passed around the cylinder may be so proportioned as to cause a proper mixture to be supplied to the internal combustion engine at all speeds and due to the large openings through which the gas flows there is relatively little resistance oifered to the inflowing gas by this carburetor. This permits the engine to get a maximum charge whenever the throttle valve is opened and materially aids in engine efiiciency. The carburetor contains no moving parts in the mixing chamber and hence is sturdy and does not easily get out of order.

In the modification shown in Figures 5 and 6, the action of the cylinder is similar to that in the first-mentioned embodiment and the by-pass opening 35 because of its particular shape causes better mixing.

lt will be understood that the embodiments above described merely illustrate some of the preferred forms of this invention, which is limited only as indicated by the appended claims.

l claim:

l. ln a carburetor, a main passage, a hollow open ended cylinder suspended in said main passage substantially axially parallel thereto, the ends of cylinder each being in the form of one turn of a helix with the ends thereof joined, said cylinder being of smaller inside diameter at a point between the ends but nearer one end thereof and tapering outwardly toward both ends.

2. In a carburetor, a main passage, a hollow open ended Cylinder suspended in said main passage substantially axially parallel the eto, the ends of said cylinder each being in the form of one turn of a helix with the ends thereof joined, the pitch of the helix on one end being greater than on the other.

8. In a carburetor', a main passage, a hol low open ended cylinder suspended in said main passage substantially axially parallel thereto, the ends of said cylinder each being in the form of one turn of a helix with the ends thereof joined, the pitch of the helix on onel end being greater than on the other, said cylinder being of smaller inside diameter at a point between the ends thereof than at said ends, and means to supply fuel to gas flowing through said cylinder.

Ll. ln a carburetor, a main passage comprising a horizontal and a vertical portion through which gas is adapted to flow, a hollow open ended cylinder suspended in said vertical portfon substantially axially aarallel thereto and near the horizontal portion, the ends of said cylinder each being in the form of one turn of a helix with the ends thereof joined, the pitch of `he helix on one end being greater than on the other, said cylinder being of smaller inside diameter at a point between the ends thereof than at said ends, and means to supply fuel to gas flowing through said cylinder.

5. In a carburetor having a main passage comprising a horizontal portion through which a gas is adapted to enter, and a vertical portion extending upward therefrom, in which fuel is adapted to be mixed with the gas and the mixture delivered therefrom, a hollow open ended cylinder of smaller diameter than said vertical passage suspended axially parallel, but offset to one side, in the lower end of said vertical passage, the ends of said cylinder each being in the form of one turn of a helix with the ends joined, and means to supply fuel to the gas flowing through said cylinder.

6. ln a carburetor having a main passage comprising a horizontal porti-on through which a gas is adapted to enter, and a vertical portion extending upward therefrom, in which fuel is adapted to be mixed with the gas and the mixture delivered therefrom, a hollow open ended cylinder of smaller diameter than said vertical passage suspended axially parallel to and in the lower end of said vertical passage, the ends of said cylinder each being in the form of one turn of a helix with the ends joined, the cylinder being sorformed that part farthest from the intake end of the horizontal passage extends farther' downward than that nearest said intake and said cylinder' being of smaller inside diameter at a point near the lower end and tapering outwardly towards both the top and bottom.

7. In a carburetor having` a main passage comprising a horizontal portion through which a gas is adapted to enter, and a vertical portion extending upward therefrom, in which fuel is adapted to be mixed with the gas and the mixture delivered therefrom, a hollow open ended cylinder of smaller diameter than said vertical passage suspended axially parallel, but offset to one side, in the lower end of said vertical passage, the ends of said cylinder each being in the form of one turn of a helix with the ends joined, means to close a part of the passage formed between said cylinder and passage.

8. ln a carburetor having a main passage comprising a horizontal portion through which a gas is adapted to enter, and a vertical portion extending upward therefrom, in which fuel is adapted to be mixed with the gas and the mixture delivered therefrom, a hollow open ended cylinder of smaller diameter than said vertical passage suspended axially parallel, but offset to one side, in the lower end of said vertical passage, the ends of said cylinder each being in the form of one turn of a helix with the ends joined, means to close substant. ally half of the passage formed between said cylinder and passage.

In testimony whereof l affix my signature.

WILLIAM M. THOMAS.

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